From January 1979 to February 1989, we studied at necropsy 22 cocaine addicts. The 22 patients were divided into 2 groups: death due to cocaine overdose (13 patients, aged 23 to 45 years(mean 32], and mean total blood cocaine level, 0.36 mg/dl) and non-cocaine related death (9 patients, aged 15 to 50 years [mean 32]). Of the 22 patients, 17 were men and 5 were women; 19 were black and 3 were white. Gross examination in the 22 patients disclosed that 8 patients (36%) had 1 or more of the 4 major (left main, left anterior descending, left circumflex, and right) coronary arteries narrowed at some point >75% in cross-sectional area by atherosclerotic plaque. In 17 cases, the 4 major epicardial coronary arteries were divided into 805 five-mm long patients with toxic blood concentrations of cocaine at necropsy, 41 (8%) of 544 five-mm coronary segments were narrowed 76 to 100% and 106 segments (19%) were narrowed 51 to 75% in cross-sectional area by plaque. Of the 5 cocaine addicts in whom death was not related to cocaine use, 8 (3%) of 261 five-mm coronary segments were narrowed 76 to 100% and 19 segments (7%) were narrowed 51 to 75% in cross-sectional area by plaque. These findings suggest that the frequency of coronary artery narrowing is greater in patients who die shortly after taking cocaine compared to those with death not due to cocaine overdose. Also the frequency of severe coronary arterial narrowing is considerably greater than expected for the entire group of patients whose mean age was only 32 years.